source3/smbd/blocking.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Blocking Locking functions
   4    Copyright (C) Jeremy Allison 1998-2003
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "includes.h"
  22 #undef DBGC_CLASS
  23 #define DBGC_CLASS DBGC_LOCKING
  24
  25 /****************************************************************************
  26  This is the structure to queue to implement blocking locks.
  27  notify. It consists of the requesting SMB and the expiry time.
  28 *****************************************************************************/
  29
  30 typedef struct _blocking_lock_record {
  31         struct _blocking_lock_record *next;
  32         struct _blocking_lock_record *prev;
  33         int com_type;
  34         files_struct *fsp;
  35         time_t expire_time;
  36         int lock_num;
  37         SMB_BIG_UINT offset;
  38         SMB_BIG_UINT count;
  39         uint32 lock_pid;
  40         enum brl_flavour lock_flav;
  41         enum brl_type lock_type;
  42         char *inbuf;
  43         int length;
  44 } blocking_lock_record;
  45
  46 /* dlink list we store pending lock records on. */
  47 static blocking_lock_record *blocking_lock_queue;
  48
  49 /* dlink list we move cancelled lock records onto. */
  50 static blocking_lock_record *blocking_lock_cancelled_queue;
  51
  52 /****************************************************************************
  53  Destructor for the above structure.
  54 ****************************************************************************/
  55
  56 static void free_blocking_lock_record(blocking_lock_record *blr)
  57 {
  58         SAFE_FREE(blr->inbuf);
  59         SAFE_FREE(blr);
  60 }
  61
  62 /****************************************************************************
  63  Determine if this is a secondary element of a chained SMB.
  64   **************************************************************************/
  65
  66 static BOOL in_chained_smb(void)
  67 {
  68         return (chain_size != 0);
  69 }
  70
  71 static void received_unlock_msg(int msg_type, struct process_id src,
  72                                 void *buf, size_t len);
  73
  74 /****************************************************************************
  75  Function to push a blocking lock request onto the lock queue.
  76 ****************************************************************************/
  77
  78 BOOL push_blocking_lock_request( char *inbuf, int length,
  79                 files_struct *fsp,
  80                 int lock_timeout,
  81                 int lock_num,
  82                 uint32 lock_pid,
  83                 enum brl_type lock_type,
  84                 enum brl_flavour lock_flav,
  85                 SMB_BIG_UINT offset, SMB_BIG_UINT count)
  86 {
  87         static BOOL set_lock_msg;
  88         blocking_lock_record *blr, *tmp;
  89         struct byte_range_lock *br_lck = NULL;
  90         NTSTATUS status;
  91
  92         if(in_chained_smb() ) {
  93                 DEBUG(0,("push_blocking_lock_request: cannot queue a chained request (currently).\n"));
  94                 return False;
  95         }
  96
  97         /*
  98          * Now queue an entry on the blocking lock queue. We setup
  99          * the expiration time here.
 100          */
 101
 102         if((blr = SMB_MALLOC_P(blocking_lock_record)) == NULL) {
 103                 DEBUG(0,("push_blocking_lock_request: Malloc fail !\n" ));
 104                 return False;
 105         }
 106
 107         blr->next = NULL;
 108         blr->prev = NULL;
 109
 110         if((blr->inbuf = (char *)SMB_MALLOC(length)) == NULL) {
 111                 DEBUG(0,("push_blocking_lock_request: Malloc fail (2)!\n" ));
 112                 SAFE_FREE(blr);
 113                 return False;
 114         }
 115
 116         blr->com_type = CVAL(inbuf,smb_com);
 117         blr->fsp = fsp;
 118         blr->expire_time = (lock_timeout == -1) ? (time_t)-1 : time(NULL) + (time_t)lock_timeout;
 119         blr->lock_num = lock_num;
 120         blr->lock_pid = lock_pid;
 121         blr->lock_flav = lock_flav;
 122         blr->lock_type = lock_type;
 123         blr->offset = offset;
 124         blr->count = count;
 125         memcpy(blr->inbuf, inbuf, length);
 126         blr->length = length;
 127
 128         br_lck = brl_get_locks(NULL, blr->fsp);
 129         if (!br_lck) {
 130                 DLIST_REMOVE(blocking_lock_queue, blr);
 131                 free_blocking_lock_record(blr);
 132                 return False;
 133         }
 134
 135         /* Add a pending lock record for this. */
 136         status = brl_lock(br_lck,
 137                         lock_pid,
 138                         procid_self(),
 139                         offset,
 140                         count,
 141                         PENDING_LOCK,
 142                         blr->lock_flav,
 143                         lock_timeout);
 144         TALLOC_FREE(br_lck);
 145
 146         if (!NT_STATUS_IS_OK(status)) {
 147                 DEBUG(0,("push_blocking_lock_request: failed to add PENDING_LOCK record.\n"));
 148                 DLIST_REMOVE(blocking_lock_queue, blr);
 149                 free_blocking_lock_record(blr);
 150                 return False;
 151         }
 152
 153         DLIST_ADD_END(blocking_lock_queue, blr, tmp);
 154
 155         /* Ensure we'll receive messages when this is unlocked. */
 156         if (!set_lock_msg) {
 157                 message_register(MSG_SMB_UNLOCK, received_unlock_msg);
 158                 set_lock_msg = True;
 159         }
 160
 161         DEBUG(3,("push_blocking_lock_request: lock request length=%d blocked with expiry time %d (+%d) \
 162 for fnum = %d, name = %s\n", length, (int)blr->expire_time, lock_timeout,
 163                 blr->fsp->fnum, blr->fsp->fsp_name ));
 164
 165         /* Push the MID of this packet on the signing queue. */
 166         srv_defer_sign_response(SVAL(inbuf,smb_mid));
 167
 168         return True;
 169 }
 170
 171 /****************************************************************************
 172  Return a smd with a given size.
 173 *****************************************************************************/
 174
 175 static void send_blocking_reply(char *outbuf, int outsize)
 176 {
 177         if(outsize > 4)
 178                 smb_setlen(outbuf,outsize - 4);
 179
 180         if (!send_smb(smbd_server_fd(),outbuf))
 181                 exit_server("send_blocking_reply: send_smb failed.");
 182 }
 183
 184 /****************************************************************************
 185  Return a lockingX success SMB.
 186 *****************************************************************************/
 187
 188 static void reply_lockingX_success(blocking_lock_record *blr)
 189 {
 190         char *outbuf = get_OutBuffer();
 191         int bufsize = BUFFER_SIZE;
 192         char *inbuf = blr->inbuf;
 193         int outsize = 0;
 194
 195         construct_reply_common(inbuf, outbuf);
 196         set_message(outbuf,2,0,True);
 197
 198         /*
 199          * As this message is a lockingX call we must handle
 200          * any following chained message correctly.
 201          * This is normally handled in construct_reply(),
 202          * but as that calls switch_message, we can't use
 203          * that here and must set up the chain info manually.
 204          */
 205
 206         outsize = chain_reply(inbuf,outbuf,blr->length,bufsize);
 207
 208         outsize += chain_size;
 209
 210         send_blocking_reply(outbuf,outsize);
 211 }
 212
 213 /****************************************************************************
 214  Return a generic lock fail error blocking call.
 215 *****************************************************************************/
 216
 217 static void generic_blocking_lock_error(blocking_lock_record *blr, NTSTATUS status)
 218 {
 219         char *outbuf = get_OutBuffer();
 220         char *inbuf = blr->inbuf;
 221         construct_reply_common(inbuf, outbuf);
 222
 223         /* whenever a timeout is given w2k maps LOCK_NOT_GRANTED to
 224            FILE_LOCK_CONFLICT! (tridge) */
 225         if (NT_STATUS_EQUAL(status, NT_STATUS_LOCK_NOT_GRANTED)) {
 226                 status = NT_STATUS_FILE_LOCK_CONFLICT;
 227         }
 228
 229         if (NT_STATUS_EQUAL(status, NT_STATUS_FILE_LOCK_CONFLICT)) {
 230                 /* Store the last lock error. */
 231                 files_struct *fsp = blr->fsp;
 232
 233                 fsp->last_lock_failure.context.smbpid = blr->lock_pid;
 234                 fsp->last_lock_failure.context.tid = fsp->conn->cnum;
 235                 fsp->last_lock_failure.context.pid = procid_self();
 236                 fsp->last_lock_failure.start = blr->offset;
 237                 fsp->last_lock_failure.size = blr->count;
 238                 fsp->last_lock_failure.fnum = fsp->fnum;
 239                 fsp->last_lock_failure.lock_type = READ_LOCK; /* Don't care. */
 240                 fsp->last_lock_failure.lock_flav = blr->lock_flav;
 241         }
 242
 243         ERROR_NT(status);
 244         if (!send_smb(smbd_server_fd(),outbuf)) {
 245                 exit_server("generic_blocking_lock_error: send_smb failed.");
 246         }
 247 }
 248
 249 /****************************************************************************
 250  Return a lock fail error for a lockingX call. Undo all the locks we have
 251  obtained first.
 252 *****************************************************************************/
 253
 254 static void reply_lockingX_error(blocking_lock_record *blr, NTSTATUS status)
 255 {
 256         char *inbuf = blr->inbuf;
 257         files_struct *fsp = blr->fsp;
 258         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 259         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT) 0;
 260         uint32 lock_pid;
 261         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 262         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 263         char *data;
 264         int i;
 265
 266         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 267
 268         /*
 269          * Data now points at the beginning of the list
 270          * of smb_lkrng structs.
 271          */
 272
 273         /*
 274          * Ensure we don't do a remove on the lock that just failed,
 275          * as under POSIX rules, if we have a lock already there, we
 276          * will delete it (and we shouldn't) .....
 277          */
 278
 279         for(i = blr->lock_num - 1; i >= 0; i--) {
 280                 BOOL err;
 281
 282                 lock_pid = get_lock_pid( data, i, large_file_format);
 283                 count = get_lock_count( data, i, large_file_format);
 284                 offset = get_lock_offset( data, i, large_file_format, &err);
 285
 286                 /*
 287                  * We know err cannot be set as if it was the lock
 288                  * request would never have been queued. JRA.
 289                  */
 290
 291                 do_unlock(fsp,
 292                         lock_pid,
 293                         count,
 294                         offset,
 295                         WINDOWS_LOCK);
 296         }
 297
 298         generic_blocking_lock_error(blr, status);
 299 }
 300
 301 /****************************************************************************
 302  Return a lock fail error.
 303 *****************************************************************************/
 304
 305 static void blocking_lock_reply_error(blocking_lock_record *blr, NTSTATUS status)
 306 {
 307         switch(blr->com_type) {
 308 #if 0
 309         /* We no longer push blocking lock requests for anything but lockingX and trans2. */
 310         case SMBlock:
 311         case SMBlockread:
 312                 generic_blocking_lock_error(blr, status);
 313                 break;
 314 #endif
 315         case SMBlockingX:
 316                 reply_lockingX_error(blr, status);
 317                 break;
 318         case SMBtrans2:
 319         case SMBtranss2:
 320                 {
 321                         char *outbuf = get_OutBuffer();
 322                         char *inbuf = blr->inbuf;
 323                         construct_reply_common(inbuf, outbuf);
 324                         /* construct_reply_common has done us the favor to pre-fill the
 325                          * command field with SMBtranss2 which is wrong :-)
 326                          */
 327                         SCVAL(outbuf,smb_com,SMBtrans2);
 328                         ERROR_NT(status);
 329                         if (!send_smb(smbd_server_fd(),outbuf)) {
 330                                 exit_server("blocking_lock_reply_error: send_smb failed.");
 331                         }
 332                         break;
 333                 }
 334         default:
 335                 DEBUG(0,("blocking_lock_reply_error: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 336                 exit_server("PANIC - unknown type on blocking lock queue");
 337         }
 338 }
 339
 340 #if 0
 341 /* We no longer push blocking lock requests for anything but lockingX and trans2. */
 342
 343 /****************************************************************************
 344  Attempt to finish off getting all pending blocking locks for a lockread call.
 345  Returns True if we want to be removed from the list.
 346 *****************************************************************************/
 347
 348 static BOOL process_lockread(blocking_lock_record *blr)
 349 {
 350         char *outbuf = get_OutBuffer();
 351         char *inbuf = blr->inbuf;
 352         ssize_t nread = -1;
 353         char *data, *p;
 354         int outsize = 0;
 355         SMB_BIG_UINT startpos;
 356         size_t numtoread;
 357         NTSTATUS status;
 358         files_struct *fsp = blr->fsp;
 359
 360         numtoread = SVAL(inbuf,smb_vwv1);
 361         startpos = (SMB_BIG_UINT)IVAL(inbuf,smb_vwv2);
 362
 363         numtoread = MIN(BUFFER_SIZE-outsize,numtoread);
 364         data = smb_buf(outbuf) + 3;
 365
 366         status = do_lock(fsp,
 367                         (uint32)SVAL(inbuf,smb_pid),
 368                         (SMB_BIG_UINT)numtoread,
 369                         startpos,
 370                         READ_LOCK,
 371                         WINDOWS_LOCK,
 372                         (int32)-1);
 373
 374         if (NT_STATUS_V(status)) {
 375                 if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 376                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 377                         /*
 378                          * We have other than a "can't get lock"
 379                          * error. Send an error.
 380                          * Return True so we get dequeued.
 381                          */
 382                         generic_blocking_lock_error(blr, status);
 383                         return True;
 384                 }
 385
 386                 /*
 387                  * Still waiting for lock....
 388                  */
 389
 390                 DEBUG(10,("process_lockread: failed to get lock for file = %s. Still waiting....\n",
 391                           fsp->fsp_name));
 392                 return False;
 393         }
 394
 395         nread = read_file(fsp,data,startpos,numtoread);
 396
 397         if (nread < 0) {
 398                 generic_blocking_lock_error(blr,NT_STATUS_ACCESS_DENIED);
 399                 return True;
 400         }
 401
 402         construct_reply_common(inbuf, outbuf);
 403         outsize = set_message(outbuf,5,0,True);
 404
 405         outsize += nread;
 406         SSVAL(outbuf,smb_vwv0,nread);
 407         SSVAL(outbuf,smb_vwv5,nread+3);
 408         p = smb_buf(outbuf);
 409         *p++ = 1;
 410         SSVAL(p,0,nread); p += 2;
 411         set_message_end(outbuf, p+nread);
 412
 413         DEBUG(3, ( "process_lockread file = %s, fnum=%d num=%lu nread=%ld\n",
 414                    fsp->fsp_name, fsp->fnum, (unsigned long)numtoread, (long)nread ) );
 415
 416         send_blocking_reply(outbuf,outsize);
 417         return True;
 418 }
 419
 420 /****************************************************************************
 421  Attempt to finish off getting all pending blocking locks for a lock call.
 422  Returns True if we want to be removed from the list.
 423 *****************************************************************************/
 424
 425 static BOOL process_lock(blocking_lock_record *blr)
 426 {
 427         char *outbuf = get_OutBuffer();
 428         char *inbuf = blr->inbuf;
 429         int outsize;
 430         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 431         NTSTATUS status;
 432         files_struct *fsp = blr->fsp;
 433
 434         count = IVAL_TO_SMB_OFF_T(inbuf,smb_vwv1);
 435         offset = IVAL_TO_SMB_OFF_T(inbuf,smb_vwv3);
 436
 437         errno = 0;
 438         status = do_lock(fsp,
 439                         (uint32)SVAL(inbuf,smb_pid),
 440                         count,
 441                         offset,
 442                         WRITE_LOCK,
 443                         WINDOWS_LOCK,
 444                         (int32)-1);
 445
 446         if (NT_STATUS_IS_ERR(status)) {
 447                 if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 448                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 449                         /*
 450                          * We have other than a "can't get lock"
 451                          * error. Send an error.
 452                          * Return True so we get dequeued.
 453                          */
 454
 455                         blocking_lock_reply_error(blr, status);
 456                         return True;
 457                 }
 458                 /*
 459                  * Still can't get the lock - keep waiting.
 460                  */
 461                 DEBUG(10,("process_lock: failed to get lock for file = %s. Still waiting....\n",
 462                           fsp->fsp_name));
 463                 return False;
 464         }
 465
 466         /*
 467          * Success - we got the lock.
 468          */
 469
 470         DEBUG(3,("process_lock : file=%s fnum=%d offset=%.0f count=%.0f\n",
 471                  fsp->fsp_name, fsp->fnum, (double)offset, (double)count));
 472
 473         construct_reply_common(inbuf, outbuf);
 474         outsize = set_message(outbuf,0,0,True);
 475         send_blocking_reply(outbuf,outsize);
 476         return True;
 477 }
 478 #endif
 479
 480 /****************************************************************************
 481  Attempt to finish off getting all pending blocking locks for a lockingX call.
 482  Returns True if we want to be removed from the list.
 483 *****************************************************************************/
 484
 485 static BOOL process_lockingX(blocking_lock_record *blr)
 486 {
 487         char *inbuf = blr->inbuf;
 488         unsigned char locktype = CVAL(inbuf,smb_vwv3);
 489         files_struct *fsp = blr->fsp;
 490         uint16 num_ulocks = SVAL(inbuf,smb_vwv6);
 491         uint16 num_locks = SVAL(inbuf,smb_vwv7);
 492         SMB_BIG_UINT count = (SMB_BIG_UINT)0, offset = (SMB_BIG_UINT)0;
 493         uint32 lock_pid;
 494         BOOL large_file_format = (locktype & LOCKING_ANDX_LARGE_FILES);
 495         char *data;
 496         NTSTATUS status = NT_STATUS_OK;
 497
 498         data = smb_buf(inbuf) + ((large_file_format ? 20 : 10)*num_ulocks);
 499
 500         /*
 501          * Data now points at the beginning of the list
 502          * of smb_lkrng structs.
 503          */
 504
 505         for(; blr->lock_num < num_locks; blr->lock_num++) {
 506                 BOOL err;
 507
 508                 lock_pid = get_lock_pid( data, blr->lock_num, large_file_format);
 509                 count = get_lock_count( data, blr->lock_num, large_file_format);
 510                 offset = get_lock_offset( data, blr->lock_num, large_file_format, &err);
 511
 512                 /*
 513                  * We know err cannot be set as if it was the lock
 514                  * request would never have been queued. JRA.
 515                  */
 516                 errno = 0;
 517                 status = do_lock(fsp,
 518                                 lock_pid,
 519                                 count,
 520                                 offset,
 521                                 ((locktype & LOCKING_ANDX_SHARED_LOCK) ?
 522                                         READ_LOCK : WRITE_LOCK),
 523                                 WINDOWS_LOCK,
 524                                 (int32)-1);
 525
 526                 if (NT_STATUS_IS_ERR(status)) {
 527                         break;
 528                 }
 529         }
 530
 531         if(blr->lock_num == num_locks) {
 532                 /*
 533                  * Success - we got all the locks.
 534                  */
 535
 536                 DEBUG(3,("process_lockingX file = %s, fnum=%d type=%d num_locks=%d\n",
 537                          fsp->fsp_name, fsp->fnum, (unsigned int)locktype, num_locks) );
 538
 539                 reply_lockingX_success(blr);
 540                 return True;
 541         } else if (!NT_STATUS_EQUAL(status,NT_STATUS_LOCK_NOT_GRANTED) &&
 542                         !NT_STATUS_EQUAL(status,NT_STATUS_FILE_LOCK_CONFLICT)) {
 543                         /*
 544                          * We have other than a "can't get lock"
 545                          * error. Free any locks we had and return an error.
 546                          * Return True so we get dequeued.
 547                          */
 548
 549                 blocking_lock_reply_error(blr, status);
 550                 return True;
 551         }
 552
 553         /*
 554          * Still can't get all the locks - keep waiting.
 555          */
 556
 557         DEBUG(10,("process_lockingX: only got %d locks of %d needed for file %s, fnum = %d. \
 558 Waiting....\n",
 559                   blr->lock_num, num_locks, fsp->fsp_name, fsp->fnum));
 560
 561         return False;
 562 }
 563
 564 /****************************************************************************
 565  Attempt to get the posix lock request from a SMBtrans2 call.
 566  Returns True if we want to be removed from the list.
 567 *****************************************************************************/
 568
 569 static BOOL process_trans2(blocking_lock_record *blr)
 570 {
 571         extern int max_send;
 572         char *inbuf = blr->inbuf;
 573         char *outbuf;
 574         char params[2];
 575         NTSTATUS status;
 576
 577         status = do_lock(blr->fsp,
 578                         blr->lock_pid,
 579                         blr->count,
 580                         blr->offset,
 581                         blr->lock_type,
 582                         blr->lock_flav,
 583                         (int32)-1);
 584
 585         if (!NT_STATUS_IS_OK(status)) {
 586                 if (ERROR_WAS_LOCK_DENIED(status)) {
 587                         /* Still can't get the lock, just keep waiting. */
 588                         return False;
 589                 }
 590                 /*
 591                  * We have other than a "can't get lock"
 592                  * error. Send an error and return True so we get dequeued.
 593                  */
 594                 blocking_lock_reply_error(blr, status);
 595                 return True;
 596         }
 597
 598         /* We finally got the lock, return success. */
 599         outbuf = get_OutBuffer();
 600         construct_reply_common(inbuf, outbuf);
 601         SCVAL(outbuf,smb_com,SMBtrans2);
 602         SSVAL(params,0,0);
 603         send_trans2_replies(outbuf, max_send, params, 2, NULL, 0);
 604         return True;
 605 }
 606
 607
 608 /****************************************************************************
 609  Process a blocking lock SMB.
 610  Returns True if we want to be removed from the list.
 611 *****************************************************************************/
 612
 613 static BOOL blocking_lock_record_process(blocking_lock_record *blr)
 614 {
 615         switch(blr->com_type) {
 616 #if 0
 617                 /* We no longer push blocking lock requests for anything but lockingX and trans2. */
 618                 case SMBlock:
 619                         return process_lock(blr);
 620                 case SMBlockread:
 621                         return process_lockread(blr);
 622 #endif
 623                 case SMBlockingX:
 624                         return process_lockingX(blr);
 625                 case SMBtrans2:
 626                 case SMBtranss2:
 627                         return process_trans2(blr);
 628                 default:
 629                         DEBUG(0,("blocking_lock_record_process: PANIC - unknown type on blocking lock queue - exiting.!\n"));
 630                         exit_server("PANIC - unknown type on blocking lock queue");
 631         }
 632         return False; /* Keep compiler happy. */
 633 }
 634
 635 /****************************************************************************
 636  Cancel entries by fnum from the blocking lock pending queue.
 637 *****************************************************************************/
 638
 639 void cancel_pending_lock_requests_by_fid(files_struct *fsp, struct byte_range_lock *br_lck)
 640 {
 641         blocking_lock_record *blr, *next = NULL;
 642
 643         for(blr = blocking_lock_queue; blr; blr = next) {
 644                 next = blr->next;
 645                 if(blr->fsp->fnum == fsp->fnum) {
 646                         unsigned char locktype = 0;
 647
 648                         if (blr->com_type == SMBlockingX) {
 649                                 locktype = CVAL(blr->inbuf,smb_vwv3);
 650                         }
 651
 652                         if (br_lck) {
 653                                 DEBUG(10,("remove_pending_lock_requests_by_fid - removing request type %d for \
 654 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 655
 656                                 brl_lock_cancel(br_lck,
 657                                         blr->lock_pid,
 658                                         procid_self(),
 659                                         blr->offset,
 660                                         blr->count,
 661                                         blr->lock_flav);
 662
 663                                 blocking_lock_cancel(fsp,
 664                                         blr->lock_pid,
 665                                         blr->offset,
 666                                         blr->count,
 667                                         blr->lock_flav,
 668                                         locktype,
 669                                         NT_STATUS_RANGE_NOT_LOCKED);
 670                         }
 671                 }
 672         }
 673 }
 674
 675 /****************************************************************************
 676  Delete entries by mid from the blocking lock pending queue. Always send reply.
 677 *****************************************************************************/
 678
 679 void remove_pending_lock_requests_by_mid(int mid)
 680 {
 681         blocking_lock_record *blr, *next = NULL;
 682
 683         for(blr = blocking_lock_queue; blr; blr = next) {
 684                 next = blr->next;
 685                 if(SVAL(blr->inbuf,smb_mid) == mid) {
 686                         files_struct *fsp = blr->fsp;
 687                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 688
 689                         if (br_lck) {
 690                                 DEBUG(10,("remove_pending_lock_requests_by_mid - removing request type %d for \
 691 file %s fnum = %d\n", blr->com_type, fsp->fsp_name, fsp->fnum ));
 692
 693                                 brl_lock_cancel(br_lck,
 694                                         blr->lock_pid,
 695                                         procid_self(),
 696                                         blr->offset,
 697                                         blr->count,
 698                                         blr->lock_flav);
 699                                 TALLOC_FREE(br_lck);
 700                         }
 701
 702                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 703                         DLIST_REMOVE(blocking_lock_queue, blr);
 704                         free_blocking_lock_record(blr);
 705                 }
 706         }
 707 }
 708
 709 /****************************************************************************
 710   Set a flag as an unlock request affects one of our pending locks.
 711 *****************************************************************************/
 712
 713 static void received_unlock_msg(int msg_type, struct process_id src,
 714                                 void *buf, size_t len)
 715 {
 716         DEBUG(10,("received_unlock_msg\n"));
 717         process_blocking_lock_queue(time(NULL));
 718 }
 719
 720 /****************************************************************************
 721  Return the number of seconds to the next blocking locks timeout, or default_timeout
 722 *****************************************************************************/
 723
 724 unsigned blocking_locks_timeout(unsigned default_timeout)
 725 {
 726         unsigned timeout = default_timeout;
 727         time_t t;
 728         blocking_lock_record *blr = blocking_lock_queue;
 729
 730         /* note that we avoid the time() syscall if there are no blocking locks */
 731         if (!blr)
 732                 return timeout;
 733
 734         t = time(NULL);
 735
 736         for (; blr; blr = blr->next) {
 737                 if ((blr->expire_time != (time_t)-1) &&
 738                                         (timeout > (blr->expire_time - t))) {
 739                         timeout = blr->expire_time - t;
 740                 }
 741         }
 742
 743         if (timeout < 1)
 744                 timeout = 1;
 745
 746         return timeout;
 747 }
 748
 749 /****************************************************************************
 750  Process the blocking lock queue. Note that this is only called as root.
 751 *****************************************************************************/
 752
 753 void process_blocking_lock_queue(time_t t)
 754 {
 755         blocking_lock_record *blr, *next = NULL;
 756
 757         /*
 758          * Go through the queue and see if we can get any of the locks.
 759          */
 760
 761         for (blr = blocking_lock_queue; blr; blr = next) {
 762                 connection_struct *conn = NULL;
 763                 uint16 vuid;
 764                 files_struct *fsp = NULL;
 765
 766                 next = blr->next;
 767
 768                 /*
 769                  * Ensure we don't have any old chain_fsp values
 770                  * sitting around....
 771                  */
 772                 chain_size = 0;
 773                 file_chain_reset();
 774                 fsp = blr->fsp;
 775
 776                 conn = conn_find(SVAL(blr->inbuf,smb_tid));
 777                 vuid = (lp_security() == SEC_SHARE) ? UID_FIELD_INVALID :
 778                                 SVAL(blr->inbuf,smb_uid);
 779
 780                 DEBUG(5,("process_blocking_lock_queue: examining pending lock fnum = %d for file %s\n",
 781                         fsp->fnum, fsp->fsp_name ));
 782
 783                 if((blr->expire_time != -1) && (blr->expire_time <= t)) {
 784                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 785
 786                         /*
 787                          * Lock expired - throw away all previously
 788                          * obtained locks and return lock error.
 789                          */
 790
 791                         if (br_lck) {
 792                                 DEBUG(5,("process_blocking_lock_queue: pending lock fnum = %d for file %s timed out.\n",
 793                                         fsp->fnum, fsp->fsp_name ));
 794
 795                                 brl_lock_cancel(br_lck,
 796                                         blr->lock_pid,
 797                                         procid_self(),
 798                                         blr->offset,
 799                                         blr->count,
 800                                         blr->lock_flav);
 801                                 TALLOC_FREE(br_lck);
 802                         }
 803
 804                         blocking_lock_reply_error(blr,NT_STATUS_FILE_LOCK_CONFLICT);
 805                         DLIST_REMOVE(blocking_lock_queue, blr);
 806                         free_blocking_lock_record(blr);
 807                         continue;
 808                 }
 809
 810                 if(!change_to_user(conn,vuid)) {
 811                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 812
 813                         /*
 814                          * Remove the entry and return an error to the client.
 815                          */
 816
 817                         if (br_lck) {
 818                                 brl_lock_cancel(br_lck,
 819                                         blr->lock_pid,
 820                                         procid_self(),
 821                                         blr->offset,
 822                                         blr->count,
 823                                         blr->lock_flav);
 824                                 TALLOC_FREE(br_lck);
 825                         }
 826
 827                         DEBUG(0,("process_blocking_lock_queue: Unable to become user vuid=%d.\n",
 828                                 vuid ));
 829                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 830                         DLIST_REMOVE(blocking_lock_queue, blr);
 831                         free_blocking_lock_record(blr);
 832                         continue;
 833                 }
 834
 835                 if(!set_current_service(conn,SVAL(blr->inbuf,smb_flg),True)) {
 836                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 837
 838                         /*
 839                          * Remove the entry and return an error to the client.
 840                          */
 841
 842                         if (br_lck) {
 843                                 brl_lock_cancel(br_lck,
 844                                         blr->lock_pid,
 845                                         procid_self(),
 846                                         blr->offset,
 847                                         blr->count,
 848                                         blr->lock_flav);
 849                                 TALLOC_FREE(br_lck);
 850                         }
 851
 852                         DEBUG(0,("process_blocking_lock_queue: Unable to become service Error was %s.\n", strerror(errno) ));
 853                         blocking_lock_reply_error(blr,NT_STATUS_ACCESS_DENIED);
 854                         DLIST_REMOVE(blocking_lock_queue, blr);
 855                         free_blocking_lock_record(blr);
 856                         change_to_root_user();
 857                         continue;
 858                 }
 859
 860                 /*
 861                  * Go through the remaining locks and try and obtain them.
 862                  * The call returns True if all locks were obtained successfully
 863                  * and False if we still need to wait.
 864                  */
 865
 866                 if(blocking_lock_record_process(blr)) {
 867                         struct byte_range_lock *br_lck = brl_get_locks(NULL, fsp);
 868
 869                         if (br_lck) {
 870                                 brl_lock_cancel(br_lck,
 871                                         blr->lock_pid,
 872                                         procid_self(),
 873                                         blr->offset,
 874                                         blr->count,
 875                                         blr->lock_flav);
 876                                 TALLOC_FREE(br_lck);
 877                         }
 878
 879                         DLIST_REMOVE(blocking_lock_queue, blr);
 880                         free_blocking_lock_record(blr);
 881                 }
 882                 change_to_root_user();
 883         }
 884 }
 885
 886 /****************************************************************************
 887  Handle a cancel message. Lock already moved onto the cancel queue.
 888 *****************************************************************************/
 889
 890 #define MSG_BLOCKING_LOCK_CANCEL_SIZE (sizeof(blocking_lock_record *) + sizeof(NTSTATUS))
 891
 892 static void process_blocking_lock_cancel_message(int msg_type, struct process_id src,
 893                                          void *buf, size_t len)
 894 {
 895         NTSTATUS err;
 896         const char *msg = (const char *)buf;
 897         blocking_lock_record *blr;
 898
 899         if (buf == NULL) {
 900                 smb_panic("process_blocking_lock_cancel_message: null msg\n");
 901         }
 902
 903         if (len != MSG_BLOCKING_LOCK_CANCEL_SIZE) {
 904                 DEBUG(0, ("process_blocking_lock_cancel_message: "
 905                         "Got invalid msg len %d\n", (int)len));
 906                 smb_panic("process_blocking_lock_cancel_message: bad msg\n");
 907         }
 908
 909         memcpy(&blr, msg, sizeof(blr));
 910         memcpy(&err, &msg[sizeof(blr)], sizeof(NTSTATUS));
 911
 912         DEBUG(10,("process_blocking_lock_cancel_message: returning error %s\n",
 913                 nt_errstr(err) ));
 914
 915         blocking_lock_reply_error(blr, err);
 916         DLIST_REMOVE(blocking_lock_cancelled_queue, blr);
 917         free_blocking_lock_record(blr);
 918 }
 919
 920 /****************************************************************************
 921  Send ourselves a blocking lock cancelled message. Handled asynchronously above.
 922 *****************************************************************************/
 923
 924 BOOL blocking_lock_cancel(files_struct *fsp,
 925                         uint32 lock_pid,
 926                         SMB_BIG_UINT offset,
 927                         SMB_BIG_UINT count,
 928                         enum brl_flavour lock_flav,
 929                         unsigned char locktype,
 930                         NTSTATUS err)
 931 {
 932         static BOOL initialized;
 933         char msg[MSG_BLOCKING_LOCK_CANCEL_SIZE];
 934         blocking_lock_record *blr;
 935
 936         if (!initialized) {
 937                 /* Register our message. */
 938                 message_register(MSG_SMB_BLOCKING_LOCK_CANCEL,
 939                                 process_blocking_lock_cancel_message);
 940
 941                 initialized = True;
 942         }
 943
 944         for (blr = blocking_lock_queue; blr; blr = blr->next) {
 945                 if (fsp == blr->fsp &&
 946                                 lock_pid == blr->lock_pid &&
 947                                 offset == blr->offset &&
 948                                 count == blr->count &&
 949                                 lock_flav == blr->lock_flav) {
 950                         break;
 951                 }
 952         }
 953
 954         if (!blr) {
 955                 return False;
 956         }
 957
 958         /* Check the flags are right. */
 959         if (blr->com_type == SMBlockingX &&
 960                 (locktype & LOCKING_ANDX_LARGE_FILES) !=
 961                         (CVAL(blr->inbuf,smb_vwv3) & LOCKING_ANDX_LARGE_FILES)) {
 962                 return False;
 963         }
 964
 965         /* Move to cancelled queue. */
 966         DLIST_REMOVE(blocking_lock_queue, blr);
 967         DLIST_ADD(blocking_lock_cancelled_queue, blr);
 968
 969         /* Create the message. */
 970         memcpy(msg, &blr, sizeof(blr));
 971         memcpy(&msg[sizeof(blr)], &err, sizeof(NTSTATUS));
 972
 973         /* Don't need to be root here as we're only ever
 974                 sending to ourselves. */
 975
 976         message_send_pid(pid_to_procid(sys_getpid()),
 977                         MSG_SMB_BLOCKING_LOCK_CANCEL,
 978                         &msg, sizeof(msg), True);
 979
 980         return True;
 981 }